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D. L. LINDQUIST AND F. HYMANS.

ELEVATOR.

APPLICATION FILED OCT. 30, I920.

Reissued June 14, 1921. v 15,125.

3 SHEETS-SHEET I.

L I nae/lions.

3 SHEETS-SHEET 2.

ELEVATOR.

APPLICATION FILED on. 30. I920.

D. L. LINDQUIST AND F. HYMANS.

Reissued June 14 1921.

fume/Zions: K

D. L. LINDQUIST AND F. HYMANS.

ELEVATOR.

APPLICATION FILED on. 30. 1920.

Reissued June 14, 1921.

exact landing of a load car ,vioe adapted to be ope UNITED STATES PATENTOFFICE.

DAVID L. LmDQUIST, OF YONKERS, NEW YORK, AND FRED ERICK -mA.N'S, 01'

I ELEVATOR.

To all whom it may concern:

Be it known that we, Davin L. LiNo UIs'r, residing in Yonkers, in thecounty of Westchester and State of New York,- subject of the King ofSweden, and FREDERICK in Glen Ridge, county of Essex, State of ewJersey, cltizen of the Netherlands, have invented a new and usefulImprovement in Elevators, of which the following is a specification.

Our invention relates in general to load car ing devices, and isdirected more particu arly to an electrically controlled elevator orhoist.

An object of the invention is the provision of automatic means foreifecting an ing device such as an elevator car, at a re etermined pointor points regardless of t e load and speed of the device.

Other objects of the invention will appear hereinafter, the novelcombinations of elements being pointed out in the appended claims.

In the drawings accompanying this specification, Fi re 1 represents inelevation view one em iment of our invention; Fig. 2 is an'end view ofFig. 1; Fig. 3 is a sectional view of the combined friction brake andcoupling shown in Figs. 1 and 2; Fig. 4 is an end view of Fig. 3 shownin part section; Fig. 5 is a wirin diagram of a system, of directcurrent e ectrical circuits which may be used in carrying out our invention.

Like reference characters denote similar parts in all of the figures.

Generall speaking, our invention comprises an e evator or other load caing derated at ifi'erent speeds by means of different motors, and meansfor automatically transferring the load from one motor to another motoras the load carrying device approaches its stopping int.

Itas long been recognized that one of the means for effecting anaccurate stop of an elevator car at a landing or other stopping pointconsists in reduci lll g the speed before reaching the same. is reducedHYMAN residingI speed in order to be effective must be independent ofthe load and should be a small speed of the car I Specification o1Reissued Letters Patent. Rei d J 1 1921 Original 10. 13883 27, datedNovember 5, 1918, Serial Io. 64,396,

for reissue llled October 80, 1920. Serial filed December 1, 1915.Application No. 420,840}.

fraction of the normal or full speed. a single motor is used forhoisting pur oses, it is practically impossible to effect su cient speedreduction w ere a high degree of accuracy 1n stopp1ng is ulred, and thisis true partlcularly when tlie elevator car is operated by an electricmotor at high speed under a wlde variation in load. By reason of ourinvention we are enabled to reduce the to any desired predetermined lowspeed ust before making a landng so as to insure an accurate or exactlandng regardless of the load and also resultin in other advantageswhich will be pointed 0111!} later on. se to any hoisting apparatus, itis rticularly adapted to an automatically coiit rolled 61%!8201'. h

e erring to t e drawin the articular embodlment of our inventfin theiein illustrated comprises a' cable sheave or winding drum A which in thepresent instance is operatively connected through the worm gearing to anelectric motor C although the motor and sheave A could be directlyconnected if so desired. The gearing B is also connected through acombined clutch and brake D and worm gearing E to an additlonal electricmotor F having a brake G associated therewith. The motors C and F may beof any desired kind of power units such for example as alternating ordirect current electric motors, the latter type of motor being shown byway of illustration with a view to simplicity.

The combined brake and clutch D which operates to slow down the hoistingdrum and permit a transfer of the load from the main motor C to theauxilia motor F, is shown in detail. in Figs. 3 an 4, and comprises a irof brake shoes 1, 1, adapted frictional y to engage a brake pulley 2secured on the shaft 3 of the motor 0. Each brake shoe is carried by acorresponding lever 4 pivoted at 5 to the frame 6, the other end of eachlever 4 being acted upon by compression spring 7 tending to force theshoes into frictional braking engagement with the pulley 2. In order torelease the brake shoes from the pulley 2, we provide a pair of bellcrank levers 8, 8, pivoted at 9 to the frame 6, the vertical arm of eachlever terminating While the invention lends itin a rounded nose 10 inhorizontal alinement.

with a sliding rod 11, while the horizontal 12, 12. The frame 6 1sjourna ed in the gear casing 13 and carries a worm Wheel 14 mesh ingwith a worm 15 secured to the shaft 16 of the auxiliary motor F shown inFig. 2." 'An elect omagnet 18 is arranged to operate the levers 8, 8, toeffect the releaseof the brake shoes 1, 1, andthe same comprises a fixedand movable magnet core 17 and 19, respectively, the latter, beingconnected to one arm of a bell crank lever 20, while the otherarm ofthis lever carries an-admstable screw 21 coacting with theslidmg rod 11.The 0 eration of theapparatus. is as follows: Wlien all parts are atrest, the magnet 180i the combined brake and clutch D is deenergized andthe brake shoes 1, 1, are applied thus coupling the wmdmgdrumi A up tothe auxiliary motor F which is prevented from. accidental rotation byreason of the brake G which is applied at this time. The first step inthe operation is to excite the magnet 18 to release the brake shoes 1,1,

and to close a circuit to the main motor C.

This resultsin severing all connection between the hoisting drum and theauxiliary motor F, and allows the motor C to startthe load, and after ashort period of acceleration,

operate the latter at full normal runnin drive the auxiliarymotorthrough the gearing E, but themotor F will not rotate at this time,since it is revented from doing so by the brake G. is efl'ect thereforeof the brake clutch D is that of an ordinary friction brake which wouldeventually bring the hoistin apparatus to rest. 'When the speed of theatter has been reduced to a suflicient extent, the brake G and the motorF are energized and the latter drives the load at a very low speed sincethe motor F acts on the load through a double gear reduction comprisingthe worm gearing E and B. This slow speed is a constant speed regardlessof the load and is maintained until the load substantially reaches thelanding whereupon the circuit to motor F is interrupted and the brake Gapplied to stop and hold the load exactly at the landing.

It will be observed that when the load carrying device is being drivenat slow speed by the auxiliary motor F, the maximum torque which can beexerted upon the hoisting drum is limited to the friction existingbetween the brakeshoes, 1, 1, and the'pulley 2. This feature is of greatpractical value particularly in the case of inclined railways chinery orother arts, w

or ammunition hoists having a positive or head-on landing stop. Underthe usual practice, failure to stop at-the proper-instant is almostcertain to'damage the hoisting maereas by means of our invention t estopping point is approached at a very low speed and even though theauxiliary motor should not be i cut 0 from the source of power at theproper instant the brake shoes 1, 1, would merely slip upon the pulley2. With proper design the torque transmitted by the brake clutch D.may'easily be kept within limits which will not permit excessive strainson the hoisting, apparatus or other parts in caseof overf run. I

Referring to Fig. 5, we show a system of direct current circuits whichmaybe used where the main and auxiliary motors C and F, respectively,are direct current shunt carrying device adapted automatically to beoperated by push buttons arranged .in the car and at each floor landing.R and R designate the switches for starting, stop ing and reversing themain motor C while I is a starting resistance automaticallv controlledthe accelerating magnet J. he parts 1', 1- K and J in like mannercontrol the starting, stopping, reversing and accelerating respectively,of the auxiliary motor F. i represents a floor controller which isoperated by some moving part of the hoisting, a paratus such as thewinding drum in t e usual way, and the same, actmg in conjunction withthe relay L, effects the transfer of. theload from the main to theauxiliary motor at the proper timein accordance with the position of thecar with respect to a desig 105 nated floor landing or other stoppingpoint. 1 If desired the floor controller may comprise a series ofswitches the hatchway operated by the car or counterweight eitherarrangement of floor controller being well known in 110 i the art. Asindicated on the drawing, the

s stem of push buttons is arranged for three oor landings and the car isat rest at the second floor.

Theoperation is as follows A person-on 1 15 "the ground floor desiringto use the elevator,

presses the button 22 at that floor. This establishes a circuit from themain.

through the door contacts 23, through the reversely woundmagnet coils ofthe magnet 1120 24, contacts 25, push button 22, winding of the floorrelay 26, to the contact 27 of the floor controller I, The circuitcontinues through the segment28 and contact 29 to the winding of thereversin completed by way of t e conductor 30 to the main.- Thereversing switch R and floor relay 26 both operate to close theirrespective contacts, the switch R closing circuitsto the motor C throughthe starting m- 130 wound electric motors. In this figure, H representsan elevator car or other load switch R and is sistance K, andsimultaneously opening any possible circuitto the auxiliary motorthrough the bottom contacts of the switch as long as the switch is inraised position. 'The operation of the relay 26 establishes a selfholdin v circuit comprising the left hand winding of the magnet 24 andresistance 31, this circuit being in shunt to the circuit including thecontacts 25 and the ash button 22. In consequence of this self ioldincircuit, the contacts 25 become separatell and hence the other floorbuttons are rendered dead and there can be no interference in theoperation in case another of the buttons be operated. As the motorstarts to build up a counter-electro-motive force, the acceleratingmagnet automatically and gradually short-circuits the startingresistance J in a well-known way and the motor quickly runs up to fullnormal speed. In the meantime the relay L having its operating magnetconnected in direct shunt to the main motor armature separates itscontacts 32.

It will be observed that the closing of the reversing switch R completesa circuit to the magnet 18 of the brake clutch D at the contact 34,hence the brake shoes 1, 1, are re leased from frictional engagementwith the pulley 2 and the auxiliar motor F is entirely disconnected fromt 1e hoisting apparatus.

The main motor continues to operate the hoisting ap aratus at full speedwhile the floor contro ler is slowly being revolved in aclockwisedirection until finally as the car approaches the ground floor,the contact 27 of the floor controller brid es the segment 28 andcontact 35. A circuit in parallel to the magnet'of the reversing switchR is now closed, said circuit comprising the contact 35, segment 36,contact 37, and the winding of the reversing switch 1'. The latter atonce closes its contacts to establish the roper connections for theauxiliary motor and brake G but neither of them as yet receives currentfrom the main line since their circuit is still open at the contacts 32of the relay L and also at the bottom contacts of the reversing switch.As .the floor controller continues to revolve, the contact 27 runs offof the segment 28 and hence the circuit to the reversing switch R isinterrupted and the switch drops its contacts thereby opening thecircuits of the main motor C and the circuit to the winding 18 of thebrake clutch D. The latter now acts as a brake on the hoisting apparatusand the speed of the car is gradually reduced. As the s )eed of themotor C falls off, its counter-electro-motive force becomes less andless until finally the relay L is unable longer to maintain its core inraised position and the contacts 32 are connected tother. The circuit tothe auxiliary motor and brake G is now completed at these contacts andthe motor F automatically takes up the load and operates it at greatlyreduced speed. Just. as the load reaches the landing, or in an instantbefore, as the case may be, the floor controller rotates the contact 35out of engagement with the contact 27, and the circuit, including thefloor re lay 26 and reversing switch 1'' is interrupted at this point.The switch r immediatel opens the circuit of the auxiliary motor 1 andeffects the application of the brake G to stop the hoist exa'ctl at thefloor landing.

If one or the other landing push buttons be operated, the car willautomatically respond and come to rest at the corresponding floorlanding just as in the case of the button 22 just described, the floorcontroller I automatically controllin both of the motors in everylnstance in oth directions of car travel.

The operation from one of the push buttons in the car is in effect thesame as that produced by a floor button although the operating circuitis somewhat dilferent. For example, upon pressing the button 22' in thecar, a circuit is closed from the main through the door contacts 23,left hand winding of the magnet 24, wire 38, winding of magnet 39,through the push button 22 floor relay 26, contacts 37 and 29 of thefloor controller and through the reversing switch magnet it to the main.The magnet 24 immediately so arates the contacts 25 to prevent an intererence from the floor buttons, while t e ma 'net 39 closes its conmm; toestablish a self holding circuit for both of the magnets 24 and 39including the door contacts 23 and resistance 40. This self holdingcircuit is maintained after the floor controller has effected the stopof the car at the designated floor landing and is not broken until thelanding door has first been opened, thereby opening one of the doorcontacts 23, and the door then closed. This safety feature prevents anyoperation from a floor button unless and until the operator in the carhas first restored the system to initial position by opening and thenclosing a door.

In reviewing the operation, it will be observed that the load istransferred from the main motor to the auxiliary motor only after thespeed of the 'car has been very materially reduced, and in every casethe amount of speed reduction is Ipredetermined and controlled b therelay The latter may readily be esigned or adjusted in any of the wellknown ways, such for example as by means of a set screw 41, to shortcircuit its contacts at any predetermined speed reduction of the motorso as to obtain the best results in practice. While the relay L suppliesa simple means for determining when the auxiliary motor will take holdof the load, it is obvious that any other device 50 v '1 at constantspeed with varying loads.

Y responsive to speed conditiomsuch for ex- It is desirable that or loadcarryin device shall first be reduced to'a speed'su stantially thesamepas the ample asa centrifugal governor,would efiect a'slmilar'result.

speed of the car normal speed of the auxiliary motor before theciricuit'to the latter is closed and its brake G released in order? that theauxiliary motor may takeupjthe load without any shock or 'ar, In some'cajsesit'may be desired to e ecta fullstop'oflthe load carryin devicebefore a landingisreac'hed and beiore the auxiliary motor is broughtlnto operation. This may readily be done merely adjusting the relay L orother speed responsive device so that it will not establish theauxiliary motor circuit until the main motor has either completely orsubstantially come to rest. i

In order that the load carrying device shall invariably stoplevelfwith afloor or exactly at a given point. inits travel, it

is essential that the speed be substantially reduced before the stoppingpoint is reached and that the load from then on shall be operated at aconstant low speed re gardless of the'loadL; TlllS necessitates aconstant speed auxiliary motor regardless of what type it may be. Inthe. particular embodiment of our invention this motor is so when theresistance of the motor armature represented as a shunt; wound directcurrent electric motor operating directly across the line, and itis'well "known that it is the] inherent characteristic of such a motorto run at afixed speed even though the load varies within wide limits"and particularly ismade as low as possible. If an alternating currentinduction motor is used in place of a direct current motor, the systemof electric circuits wouldjof course have to be modified somewhat so as.to be adapted -to that type of motor, but the alternating current motorwill operateat constant speed.

' even though the load varies, since such motor is inherently a constantspeed motor.

Other motors, such as steam, hydraulic, etc.,

could also be used providing they be suitably governed as is customaryso as to operate In any event, it is intended that the aux a iliarymotor be arranged to operate the load at a comparatively low speed,whereas the main motor may operate the load at any speed desired.

From the foregoing, it is obvious that the a paratus disclosedis capableof being modi ed in many ways without departing from the spirit andscope of our invention,

1 andtherefore we desire not to be limited to the precise constructionand arrangement of arts herein set forth. a

hat we claim is: k y, i y

1; In an elevator,"the combination of a other motor as: the car"approaches a prede;

termined stopping point.

3. In an, elevator, the combination of a car, two motors operativelyconnected therewith, and means dependent upon the position of the'carwith; respect to a predetermined point in its travel and upon its speedfor transferring the load from one motor to the other. I

4. In an elevator, the combination of a car, a motor connectedtherewith, automatic means for retardingsaid motor as the car approachesa predetermined stopping point, and an additional motor adapted to beconnected to drive the, car at:a constant slow speed after the speed, ofthe latter has been reduced a predetermined amount.

5. In an elevator, the combination of a car, a motor connected to drivethe car, means for retardinggthe speed of said motor as the carapproachesa predetermined stopping point, a second motor, adapted to beoperativelyconnected to the'car' upon the operation of saidmotor-retarding means, and means dependent on. the speed of the car for.automatically controlling said second motor, :2 i v 6.,In an elevator,the combinationv of a .car, a motor connected to drive the car,

means, for retarding the speed of said motor as the car approachesapredetermined stopping point, a second motor adapted to be operatlvelyconnected to the can upon the operation of said motor-retardin means,and means dependent on the s e of the car for automatically startingsald second motor.

7. In an elevator, thecombination of two car, main and. auxiliaryhoisting -motors electric hoisting motors-and means for closing the linecircuit to onesof said motors in accordance with thecounter-electro-motive force of theother motor.

8. In an electric elevator, the combination of two hoisting motors,means for disconnecting one of the said motors from the car upon startinthecar, and means for again connecting t e said motor and car after thespeed of the other motor has been reduced a predetermined amount.

9. In an electric elevator, the combination of two hoisting motors,electro-responsive means. for disconnecting oneof the said motors. fromthe carupon starting the car and for again connectin the said motorandcar after the speed of t e other motor has been reducedapredetermined amount.

10. In an elevator, the combinationof an electric hoistin motor adaptedto drive the car at normal glll speed, an additionalelectric motoradapted to drive the car at a reduced speed, an electrically controlledfriction clutch between said additional motor and the car,electro-responsive means for simultaneously releasing said clutch andclosing a circuit to the motor for full speed operation of the car,automatic means for applying said clutch and interrupting the circuit ofsaid last named motor as the car approaches a redetermined stoppingpoint, means dependent for its operation upon a predetermined speedreduction of the car for closin a circuit to the additional motorwhereby tie latter operates to drive the car at reduced speed, a brakefor the additional motor, and means for interrupting the circuit of saidadditional motor and applying the brake to stop the car at thepredetermined stopping point.

11. In an elevator stem, comprisi a car, hoisting cables, hoisting motormec nism, and a brake pulley and shaft therefor to operate the car, arevolving pressure means, comprising a shaft and lever,-to con- .nectthe car and the said motor mechanism together, the said shafts beingseparate and a stationary releasin means to release the pressure meansto isconnect the car from the motor mechanism.

12. In an elevator system, comprisin a car, hoisting cables, hoistinmotor mec am'sm, and a brake pulley ang shaft therefor to operate thecar, a revolving pressure means, comprising a shaft and lever, toconnect the car and the said motor mechanism together, the said shaftsbeing separate, and a stationary releasing means, comprisin a. lever, torelease the pressure means to isconnect the car from the motormechanism.

13. In an elevator system,--comprising a car and main and auxiliaryhoisting motors, a brake pulley and shaft therefor, a revolving pressuremeans, comprising a shaft and a lever, to connect the-car and theauxiliary hoisting motor to ther, the said shafts being separate, and astationary releasing means, to release ,the pressure to disconnect thecar from the auxillaryhoisting motor.

14. In an elevator system, comprising a 15. In an elevator system,comprising a car andmain and auxiliary hoisting motors, a brake pulleyand shaft therefor, a revolvin pressure means, comprising a shaft and afiver, to connect the car and the auxiliary hoisting motor together, thesaid shaftsbeing separate, an a stationary releasing means, comprising alever to release the pressure means to disconnect the car from theauxiliary hoisting motor, and connections between the said pressure andreleasin means.

11 testimony whereof we have signed our names to this specification this27th day of October, 1920.

DAVID L. LINDQUIST.

FREDERICK HYMANS.

ther, the said. shafts be- 60

